Gravity lubricating system



April 25, 1933-. G. F.' THOMAS ET AL 1,905,527

GRAVITY LUBRICATNG SYSTEM Filed March l5, 1928 l @y @LU mw Patented Apr. 25, 1933 y UNITED STATES GEORGE F. THOMAS, or BERWYN,

' ons To ALEMITE WARE AND OTTO J. HERB, CORPORATION, OF CHICAGO, ILLINOIS, A CORPORATION F DELA- PATENT OFFICE OF CIIIICAGO, ILLINOIS, ASSIGN- G-RAVITY LUBRICATING- SYSTEM Application led March 15, 1928. Serial No. 261,779.

Our invention relates, generally, to lubrieating apparatus and more particularly to a gravity system and apparatus for lubrication of a plurality of bearings from a single source in which means are provided for ad-y justing the liow to each individual bearing.

It is an object of our invention to provide an improved gravity lubricating system for a plurality of bearings in which the flow of lubricant to each of the bearings may be easily and conveniently adjusted. v

A further object is to provide an improved adjustable sight feed resistance unit, in which a gauge is provided which at all times gives a readily observable indication of the rate of feed. A further object is to provide an improved resistance unit, all characteristics of the operation of which are visible to the operator. f v

Other objects will appear from the following description, reference being had to the accompanying drawing, in which Fig. 1 isa diagrammatical vertical sectional view of an illustrative gravity system, two of the resistance units being shown in elevation;l y

Fig; 2 is a central vertical section of a modified form of resistance unit; and

Fig. 3 is a similar view of a second modified form.

-The source of lubricant in our improved system comprises a reservoir 4 having a base casting 6 and a cylindrical wall 8 secured to the casting. Aremovable cover lOits over the top of the cylindrical wall `8. A strainer 12, preferably of wire mesh, is secured at the lower end lof the cylindrical portion of the reservoir 4 and rests upon a shoulder 14 formed in the casting 6. A gauge glass 16 is secured to the reservoir 4 in any suitable manner.

The base casting 6 slopes toward a central outlet port 18 which has a suitable seat 20 at its upper edge. A float 22 of cork or other suitable material has a ballvalve 24 secured thereto by a wire 26 which passes through the cork float 22 and is bent over the top thereof. Whe the reservoir 4 is illedor partially illed with lubricant the float will rise upwardly until it comes in contact with the strainer screen 12, thus permitting lubricant to flow from the reservoir into the outlet passage 18. As the reservoir becomes empty the loat will drop, permitting the ball 24 to rest against its seat 20, thereby preyenting further flow of lubricant from the reservoir. It is desirable thus to out oi the iiow from the reservoir tothe conduit system when the lubricant is substantially exhausted from the reservoir so as to prevent the possibility'of air being drawn into the conduit system. The presence of air in the conduit system is the cause', of inaccurate distribution of the lubricant and occasional failure to operate properly.

The base casting 6 has aksuitable bracket 28 by which the reservoir may be securedv to a part of the machine-to be lubricated. The' outlet passage 18 may beclosed by a manually operable valve 30, reciprocable in a bore 31. The stem 32 of the valve 30 is threaded in a bushing 34 which is screwed into the casting 6. Any suitable number of conduits 36 are secured to the base casting 6 by bushings 38 and communicate with the bore 31. These conduits may leadto an individual resistance unit or may be branched and one conduit supply several resistance units with lubricant.

vEach of the resistance units or flow resistance fttings'comprises a body 40 having an axial bore 42 at its lower end and being connected by a union 44 with one of the bearings 41,43, 47 to be lubricated. A glass tube 46 is held between the end of the bore 42 and the end of the Ynipple 44, suitable gaskets 45 being provided toform lubricant-tlght seals. If desired, a drip litting 48, which consists of a cone-shaped disc having horizontal flanges 90 and an aperture at the tip of the conical portion may be provided. The lubricant iowing through the resistance unit will thus form drops at thel lower end of this fitting. Suit-A their sharp edges ground off. A helical passage of very small cross sectional area is` thus formed between the plug 56 and the groove between the threads in bore 54. The

I length of this passage may be varied by manually rotating the stem 58 and thereby screwing the plug 56 into or out of the bore 54. Variation in the length of this passage causes an approximately inverse proportional variation in the iiow resistance of the fitting and inthe rate of lubricant iiow.

In operation the reservoir 4 is lled with lubricant which gradually feeds through the large strainer 12 through the out-let passage 18, since, due to the presence of lubricant, the

float 22 will have raised the ball valve 24 from its seat 20. Upon opening the valve 30 lubricant will ilow` by gravity through the conduits 36 to the resistance units and hence to the bearings associated with the units. The flow to the bearing may readily be observed `through the sight openings of the resistance vunits and by adjusting the resistance plugs 56 of the various units, thel flow to each bearing may be fixed to suit the requirements of the bearing. Compensation may thus be made for the diierences in the level of the diierent units and each fitting or unit adjusted so that its bearing will receive the desired quantity of lubricant irrespective of its position with respect to the reservoir 4. It is,"of course, understood that the reservoir will be placed at a level suiiiciently above the highest bearing of the system to provide an dequate hydrostatic head for gravitational In Fig. 2 is shown a modified form of resistance unit in which the rate of iow of lubricant to the bearing may be determined at a glance. The fitting comprises a substantially tubular body 64 which is attached to a bea-ring 66 by means of a union 68. This body 64 has suitable sight openings 70 and 72 and has glass tubes 74 and 76 secured between an internal shoulder 78, a member 80 and the nipple 68, respectively, suitable gaskets being provided to effect a lubricanttight seal at the ends of the glass tubes. A tting 80, which is threaded into the upper end of the tubular body 64, is internally threaded to receive a resistance plug 82, a

portion of the thread of which is ground off so as to provide a helical passageway between the plug and the fitting 80; The plug 82 has a kerf by which it may be screwed into the fitting 8O any desired distance, thus adjusting the length and hence the flow resistance of the helical passage between the plug and fitting. A conduit 36 leading from the source of lubricant supply may' be attached -to a member 84 in any well-known manner, such as by means of the compressing ring 86 and gland 88. `The member 84 has an outlet passage 90 of covered by a thin disc valve 92. This disc is preferably made of Empire' cloth or Vsome other suitable light fabric material which is impervious to oil; The disc is confined, so that it may move only a short distance from the face at the edge of the outlet passage 90, by a cage 94 which is rigidly secured in the member 84 and has an upwardly projecting central point 96 upon which the valve 92 rests when in open-position. This check valve construction is more fully disclosed in theA covpending application of Oscar U. Zerk, Serial No. 207,609, filed July 22, 1927, and for the present purposes may be considered as a check valve which will offer substantially no resistance to flow in one direction but will close quickly upon slight differences of pressure tending to produce flow in the opposite direction.

The shoulder 78, formed integrally with the tubular body 64, has a tapered threaded bore into which a screw 98 is threaded. The

small diameter which is normally threads of this screw are preferably ground l so that there will be a helical passage of very' small cross sectional area between the screw and the shoulder 78. The passage, however, may be greater in cross sectional area than the passage between the plug 82 and the iittin 80.

hus, in operation of the device lubricant will flow by gravity through the conduit 36 past the check valve 90 and between the plug 82 and ttin 8O and will accumulate within the glass tu e 74 but will pass outwardly therefrom through the helical passage between the screw 98 and the shoulder 7 8 and will collect atthe pointed end of the screw 98 and flow therefrom in drops so that the rate yof flow may be readily observable and measured by counting the number of drops.

Thev lubricant will accumulate within the ber 80.

When thiscondition is obtained the level i of oil lin the tube 74 will remain constant and serve not only as an indication that the oil is being, fed to the bearing but will, by its height, indicate the rate at which the o1l is iiowing to the bearing. If, however, the.y

oil fills up the tubes 74 and 72, the operator 5 will' be apprised of the fact that the bearing is clogged and not taking the proper amount of oil. The height of the column of oil which is presentin the tube 7 4 during normal operation is of course dependent upon the pressure of the lubricant at the inlet of the fitting, the flow resistance around the plug 82 and the How resistance around the plug 98. The two flow resistances may be adjusted so that, for any desired rate of flow, the oil'in the tube 74 will stand at a certain level.

In other respects the operation of the unit shown in Fig. 2 is substantially the same as that illustrated'in Fig. 1. Of course, the litting shown in Fig. l has the advantage that its rate of flow can be adjusted without taking the unit apart, whereas' that shown in Fig. 2 cannot be so readily adjusted.

In Fig. 3 we have shown a modified form of resistance unit\which has all the advantages of the type shown in Fig. 2 and the additional advantage of the type shown in Fig. l, in that its resistance may be readily adjusted without taking the unit apart. Since in its details this unit is a composite of the units shown in Figs. 1 and 2, similar reference characters have been used to designate similar parts. It is believed that from the previous description the construction and method of operation of this unit will be apparent. g

While we have shown and described particular embodiments of our invention, we d o not wishpto be limited to the details disclosed therein but desire' the scope of ourinvention to be limited only by the claims which follow.

l. In a central lubricating system, the combination of a source of lubricant, aplurality of bearings to be lubricated, conduits connecting said source with said bearings, and a lubricant llow controlling tting interposed between said conduits and each 'of said bear ings, each of said fittings comprising a pair of iow resistance passages and a transparent well intermediate said passages.

2. In a gravity lubricating system of the class described, the combination of a lubricant reservoir, a plurality of bearings located at dill'erent levels and lowertha'n said to each of said bearings, conduits connecting said fittings with said reservoir, means operable without disconnecting said conduits and littings for regulating the flow of lubricant to each of said bearings in accordance with its lubricant requirement' and position relative to said reservoir, a transparent well in each of said'ttings, an adjustable flow retarding element between said well and the bearing associated with the tting, and a reservoir, a flow metering fitting connected lcant dripping from said means on transparent conduit between said ow retarding element and said bearing.

3. In a central lubricating system, the combination of a source of lubricant, a plurality lect the lubricant which has owed through said 1passageway and to form it into readily visib e drops, and transparent means through which the drops of lubricant may be observed.

4. In a gravity lubricating system of the class described, the combination of a lubricant reservoir, a plurality of bearings located at different levels and lower than said reservoir, a iiow metering unit connected to each of Said bearings, conduits connecting said littings with said reservoir, means operable without disconnecting said conduits and fittings for regulating the flow of lubricant to each of said bearings in accordance with its lubricant requirement, a transparent lubricant collecting well in each of said fittings adapted to receive lubricanty from said unit, and adjustable means including al restricted passageway for retarding the flow of lubricant from said Well to the bearing, whereby the lubricant will be stored in said well and its level serve as an indication of the rate resistance receiving lubricant from the bottom of said well, a sight aperture beneath said low resistance whereby the'loW past said flow ,resistance may be observed, and means for conducting lubricant from said 'low resistance to a bearingto be lubricated.

6. A lubricant metering fitting comprising an inlet, means adjacent the inlet for restricting the flow of lubricant, a well for receiving the 'lubricant which has flowed through said restriction, an internally threaded opening at the bottom 'of said Well, a plug having mutilated threadsscrewed in said opening, said plug having means for collectingthe lubricant which has flowed between it and said opening into drops, a sight glass around said means on said plug whereby the drops therefrom`may be observed, and means for conducting the lubrisaid plug to a bearing to be lubricated.

7. In a central lubricating system, the

ccmbination of a source of lubricant, a fittingl adjacent each Aof said bearings, a. branch conduit system connecting said source with said fittings, metering means in each of said f1ttings, a lubricant reservoi-rin each of said fit- 5 tings, and adjustablemeans between each of said reservoirs and each of said bearings whereby the lubricant level in said reservoirs `may be varied.

In witness whereof, we hereunto subscribe our names this 5 day of March, 1928.

- GEORGE F. THOMAS.

OTTO J. HERB. 

